Abdulvahed Khaledi Darvishan; Jalal Faraji; Leila Gholami; Mohsen Khorsand
Abstract
The dynamics of rainfal erosivity (R), crop management (C) and soil erodibility (K) factors compared to the others (topography-LS and land management-P) is the most important note for the correct estimate of soil erosion at different time bases. Spatio-temporal estimates of soil erosion in the representative ...
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The dynamics of rainfal erosivity (R), crop management (C) and soil erodibility (K) factors compared to the others (topography-LS and land management-P) is the most important note for the correct estimate of soil erosion at different time bases. Spatio-temporal estimates of soil erosion in the representative paired watersheds are of particular importance due to their educational functions as well as the possibility of generalizing the results to larger areas of the country. Therefore, in the present study, while examining the dynamics of R, C and K factors in the Khamsan representative paired watershed, the distribution map of soil erosion in seasonal and annual time scales were prepared using RUSLE model for two water years of 2015-2016 and 2017-2018. The results showed that soil erosion in winter with values of 3.94 and 4.95 t ha-1 y-1 accounted for about 49 and 74% of the total erosion of the year, respectively. Considering the melting conditions in calculating the K factor for the winter along with the lack of vegetation in this season led to a higher estimate of soil erosion than other seasons. These results are in consistent with plots soil loss data recorded in different seasons and the higher concentration of suspended sediments in the rivers especially in March. In the water year of 2015-2016, the distribution of rainfalls in the autumn was much higher than in the spring, so that soil erosion in the autumn accounted for about 33% of the total erosion of the year. In the water year of 2017-2018, although the average annual soil erosion was less, but due to more distribution of erosive rainfalls in winter at the same time with the lack of vegetation on the soil surface and the soil melting, the rate of winter erosion was very high.
Mitra Tanhapour; Mohammad Ebrahim Banihabib
Abstract
Debris flow is one of the natural hazards that threats people's lives in the mountainous populated areas. Thus, it is necessary to determine the rainfall thresholds for debris flow occurrence in order to develop an effective forecasting system. In this study, the empirical thresholds of rainfall for ...
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Debris flow is one of the natural hazards that threats people's lives in the mountainous populated areas. Thus, it is necessary to determine the rainfall thresholds for debris flow occurrence in order to develop an effective forecasting system. In this study, the empirical thresholds of rainfall for the occurrence of debris flow by Hirano method were assessed in a part of Alborz mountainous basins including Gorganrood, Navrood, Neka and Babolrood. For this purpose, the rainfall hyetographs of recording rain gauges were used from the period of 1983-2004. Then, the intensity-duration rainfall thresholds (I-D threshold) for selected basins were estimated and compared with previous studies from the local, regional and global scale. The examination of rainfall thresholds for the initiation of debris flow showed that the rainfall of more than 27.2 and 14.8 mm, respectively, in the Navrood and Gorganrood watersheds and rainfall more than 37.84 and 66.12 mm, respectively, in the Babolrood and Neka basins are able to trigger debris flow during their concentration time. Comparison of the I-D threshold of this study with the results of previous studies showed I-D threshold of the studied basins generally are lower than the thresholds of local and regional but higher than global thresholds. In other words, there are some areas in the world that need smaller rainfalls for initiation debris flow in comparison to the study area. The difference among threshold of debris flow occurrence in the world’s basins comes from their variety in climatic, geographical, physiographic and geological factors.
Mohammad Sedighi; amir shahrokh amini
Abstract
The global water scarcity crisis is affecting water management in various sectors, including water and agriculture. Aquatic basins and their surrounding areas have been encountered with serious challenges such as drying up of lakes and rivers, negative aquifer balance, changes in surrounding land use, ...
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The global water scarcity crisis is affecting water management in various sectors, including water and agriculture. Aquatic basins and their surrounding areas have been encountered with serious challenges such as drying up of lakes and rivers, negative aquifer balance, changes in surrounding land use, increased cultivation of irrigated and horticultural lands, and changes in the pattern of cultivation from low-crop to high-water crops in recent years. Satellite imagery due to its wide spatial coverage, high resolution, low cost, rich time archive of satellite imagery and ease of use methods is a useful and efficient tool to help manage water and soil resources. In this study, four classes of soil, water and wet, urban and agricultural areas were selected. Then, two random forest classification methods and support vector machines are used to classify images. Classification methods were evaluated by calculating two indices of accuracy and Kappa coefficient using test data. The random forest classification in the four years, 2012, 2014, 2016 and 2018 and classification of support vector machines in two years, 2008 and 2010 have the most accuracy. Therefore, the random forest algorithm has worked well in separating the classes, especially in water basin, and can be used as a reliable method in this area.
Nasrin Mirzaee; Amirpouya Sarraf
Abstract
River runoff forecasting in watersheds has a special place in the management and planning of water resources for the design of water facilities, water intake from rivers, consumption management and etc. In the present study, the performance of some data integration models including simple averaging, ...
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River runoff forecasting in watersheds has a special place in the management and planning of water resources for the design of water facilities, water intake from rivers, consumption management and etc. In the present study, the performance of some data integration models including simple averaging, weighted averaging and integrated artificial neural network model in monthly discharge modeling has been evaluated and compared. For this purpose, monthly flow prediction in upstream basin of Jiroft Dam was examined using Artificial Neural Network (ANN) models, Adaptive Neural-Fuzzy Inference System (ANFIS), ARIMA model and Support Vector Regression (SVR) model as an individual model. Then, the individual models were trained and validated using selected predictor variables and their results were selected for use in the integration process. Large-scale climatic signals including NAO, ENSO and PDO are also used in hydrological forecasts of river flow and the performance of single and integrated models in two modes with and without considering these signals has been compared based on the evaluation of three criteria Nash-Sutcliffe (NSE), Coefficient of determination (R2) and Mean Square Error (MSE). Results of this study indicated that the integrated approach significantly increases the accuracy of predictions. In addition, large-scale climatic signals were found to improve results, especially during the test period. For example, the results of the integrated model of artificial neural network with large climatic scale signals show that this model has the best performance among the integrated models. Also, the NSE criterion has improved by 0.04 in training compared to the integrated model of artificial neural network without large-scale signals and the MSE error has been reduced by 0.001.
Masoud Eshghizadeh; Ali Talebi; Mohammad-Taghi Dastorani; Hamidreza Azimzadeh
Abstract
In this research, LAPSUS model is introduced as a suitable model to surface runoff rutting by Multiple Flow Direction (MFD) algorithms. Flow distribution algorithms grouped into two main types including Single Flow Direction (SFD) and MFD algorithms. LAPSUS model is a landscape evolution and a multi-module ...
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In this research, LAPSUS model is introduced as a suitable model to surface runoff rutting by Multiple Flow Direction (MFD) algorithms. Flow distribution algorithms grouped into two main types including Single Flow Direction (SFD) and MFD algorithms. LAPSUS model is a landscape evolution and a multi-module dynamic landscape evolution model. Studied processes included overland erosion, land sliding, tillage erosion and tectonics. Input data in LAPSUS model was DEM, rainfall, runoff coefficient and convergence factor. This model has written in C++. This model has been used for runoff rutting in Kakhk watershed of Gonabad, Iran, for the first time. For this purpose, surface runoff resulted from 34 rainfall events was simulated for multiple flow direction analysis between 2008 and 2018. Results showed that LAPSUS model can simulate total volumes of events with a high accuracy by MFD with the amount of nRMSE of 3.9 percent.
Ramin Salmasi; Mohsen Farahbakhsh; Hossein Asadi
Abstract
High soil phosphorus (P) can increase the amount of runoff P and cause pollution of P in water bodies. In this paper, to select the best method between laboratory extracting and rainfall simulator method for determining environmental threshold level of P concentration was compared. For this purpose, ...
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High soil phosphorus (P) can increase the amount of runoff P and cause pollution of P in water bodies. In this paper, to select the best method between laboratory extracting and rainfall simulator method for determining environmental threshold level of P concentration was compared. For this purpose, surface soil was sampledfrom 30 points of Talkherood Watershed inEastern Azerbayjan with widely available P contents. After determining some of general properties, four soil P tests comprising Olsen, Mehlich-3, Iron oxide, and Soltanpour were used. Water soluble P in lab was measured and runoff soluble P of soils was determined with using rainfall simulator by applying 75 mm h-1 rainfallfor 30 minutes. Relationship between P concentrations determined by four methods with a) water soluble soil P, as P loss index, and b) runoff soluble P, showed that environmental soil P concentration can be estimated by both lab extracts and rainfall simulation methods for lime soils of this region. As the lab extracts method are easier and less time-consuming, this method is recommended for threshold concentration estimation. Since in iron oxide method, slope difference between the two split-lines was greater than other methods and high correlation coefficients were obtained for all of the methods, as a result iron oxide method is better than others for threshold concentration estimation of available P concentration. Since changing point for dissolved reactive P was seen in 0.36 mg l-1 concentration, as a result this concentration is lower than environmental P concentration for eutrophication phenomenon.
Ali Akbar Davoodirad; Davood Nikkami; Mehdi Mardian
Abstract
Increasing in production and welfare of rural household along with soil erosion mitigation are the most important objects of a watershed management program. Land use optimization is an efficient approach that leads to a sustainable development plan. In this research, the land use optimization was applied ...
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Increasing in production and welfare of rural household along with soil erosion mitigation are the most important objects of a watershed management program. Land use optimization is an efficient approach that leads to a sustainable development plan. In this research, the land use optimization was applied using a two-objective linear programing model and geographic information systems by Lingo 11.0 software in Adineh-Masjed Shahzand watershed of Markazi province, Iran. The model was defined with three scenarios of current conditions, applying management conditions, and standard conditions for two objectives of maximizing net benefits and minimizing soil erosion. Results showed that the annual soil erosion decreased by 1.27, 18.69 and 26.93% in current land use, land use management, and standard land use conditions, respectively. Also annual net income decreased by 18.56% in current land use; but increased by 48.01 and 220.07% in land use management and standard land use conditions, respectively. Considering weighting value of decreased soil erosion of 1.27% that is less than weighting value of decreased net income in current conditions, land use optimization with no management practices or land standardization is not justifiable.
Alireza Habibi; Samad Shadfar; Younes Daghigh
Volume 2, Issue 1 , May 2010, , Pages 18-24
Abstract
Recognition from coverage amount of country present conditions in a watershed is unavoidable necessity for optimal and permanent development and utilization. In this research, we choose Fashand watershed in north-eastern of Hashtgerd city. First have recognized independent variables to predicting country ...
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Recognition from coverage amount of country present conditions in a watershed is unavoidable necessity for optimal and permanent development and utilization. In this research, we choose Fashand watershed in north-eastern of Hashtgerd city. First have recognized independent variables to predicting country power. Then prepared various weight maps as informational layers using field studies and Geographical Information Systems (GIS), and classified and composed them together using coverage index. In next stage, coverage predicting agriculture power map with present country conditions map and calculate correlation matrix. Results showed that predicted area with much week and week talent include intermediate rangelands with 19.47 percent coverage areas with medium talent for agriculture intensity have 0.3 percent stratification. And good and very good predicted areas for agriculture intensity include 39.7 percent, good rangelands 2 percent, poor rangelands 29 percent. Unfortunately 994 Hectares of very good agriculture rascals have specialized to civic areas that shows having no comprehensive programs in this base. Prediction shows that 9259 ha of rascals with 53.17 percent of total areas include very good agriculture lands and medium, week and very week areas include less than 23 percent of total Fashand area. Finally, we suggest that programmers and propagators present a model for each area regard to ecological power of area and present intensities conditions, to have in mind area with optimal utilization and suitable intensity use.
Reza Talaee
Abstract
In this research, a spatial prediction model (a quantitative method) and the fuzzy sets theory (a semi-quantitative method) have been used for landslide hazard and risk assessment, respectively. A procedure, compring two analytical stages, has been proposed to show the location of future slope instability. ...
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In this research, a spatial prediction model (a quantitative method) and the fuzzy sets theory (a semi-quantitative method) have been used for landslide hazard and risk assessment, respectively. A procedure, compring two analytical stages, has been proposed to show the location of future slope instability. In the first step, 75% of the pixels with landslide have been entered to the model as the estimation set, in which new landslides have occurred with a moderate to high intensity or at least have displaced once or more in the last 50 years. At the second stage, the accuracy of prediction map has been examined by ROC curve (Receiver Operating Characteristic curve) based on 25% of the landslide pixels that have not been entered in the model. Landslide risk evaluation was considered by combination of the hazard potential and resource damage potential and using the fuzzy algebraic product operator in the region. The hazard potential and resource damage potential obtained typically from the hazard zonation map and the land cover/land use map. The area under the ROC curve is 0.795 for hazard zonation map, equivalent to an accuracy of 79.5%. In the base of multi-method approach results, 13.8% of the region is located in a high and very high risk level zone, and 78.1% of the area is placed in low and very low risk categories. Proposed method was used for landslide risk assessment in Hashtchin region and the results could be used to established land use planes, developmental activities, displacement and extension of settlement area, and patterns of building regulations.
Seyed Saeed Eslamian; Mohammad Hadi Bazrkar; Seyed Farhad Mousavi
Abstract
The most important factor of drought analysis is rainfall. All resources which are supported by rainfall, such as, surface streams; groundwater and lakes, are affected by deficit of rainfall. Analysis of past rainfall statistics indicates a pattern. Forecasting future rainfall can be used in water resources ...
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The most important factor of drought analysis is rainfall. All resources which are supported by rainfall, such as, surface streams; groundwater and lakes, are affected by deficit of rainfall. Analysis of past rainfall statistics indicates a pattern. Forecasting future rainfall can be used in water resources planning. This opportunity can be provided by time series patterns. The aim of this research is drought forecasting of Isfahan Province, by fitness of various models with rainfall data. Studied models are included in monthly, monthly-seasonally, annual-exponential, moving average (3, 5, 7) and sinusoidal. 24 meteorology stations have been studied in the time series analysis. The at-site statistic period ranges between maximum 44 years (1957-2000) to minimum 11 years (1987-1997). By regarding ARIMA model fitness, the results indicate that the studied stations are divided to three groups as high, medium and low quality. These groups are included 9, 5, 4 stations, respectively. Although Isfahan and Kashan have been owned long-term rainfall data, they have less suitable fitness than the other stations. Therefore, by only having long-term rainfall data, it cannot be expected the better fitness of time series. Using ARIMA for annual moving average modeling can be effective in drought pattern analysis and have been presented the good patterns.
Mohammad Hemmati; Davood Nikkami; Hassan Ahmadi; Gholamreza Zehtabian; Mohammad Jafari
Volume 1, Issue 1 , May 2009, , Pages 21-31
Abstract
Soil is one of the four elements of life and one of the most important agricultural and rangeland production factors. Soil erosion has impact on fertility of upstream lands and indirectly causes downstream damages. On a global scale, more than 50% of rangelands and about 80% of farmlands are significantly ...
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Soil is one of the four elements of life and one of the most important agricultural and rangeland production factors. Soil erosion has impact on fertility of upstream lands and indirectly causes downstream damages. On a global scale, more than 50% of rangelands and about 80% of farmlands are significantly suffering from soil erosion and sedimentation phenomenon. Despite of agricultural benefits of rainwater, its erosive energy in the primary stages, detaches soil particles and creates surface runoff which has the most severe impacts on soil erosion. The effective energy in this shape of erosion is called rainfall erosivity, which is rainfall erosion potential and depends on rainfall physical characteristics. Some different indices are developed for quantification of rainfall erosivity. Some indices emphasise on the amount of rainfall or rain intensity. Worldwide investigations show that applying a certain index, like EI60 in USLE equation has not sufficient credit and according to climatic condition the best rainfall erosivity index should be determined. In this research, after establishing 21 erosion plots in Kaboudeh Oliya village, Kermanshah city, on two land use types of dry farming of 6, 12, 16 and 17 percent slopes and rangelands on 25, 35 and 45 percent slopes with three repetitions, 15 rainfall events which produced surface runoff were monitored by a recording rain gauge and the amount of surface runoff and sediment were measured. According to the literature, 45 rainfall erosivity indices were chosen to be compared. For facilitating and increasing accuracy of calculations on rainfall erosivity indices, a computer program was developed to analyze and extract necessary factors from each storm. The result showed that in the study area, EI60 is the best rainfall erosivity index and has maximum correlation coefficient of 0.721 with soil loss.
Ali Reza Eslami; Abdol Rasoul Telvari
Abstract
The hydrologic events and physical structure of a basin is related to governing climatic conditions. Basins have different hydrologic responses considering their various morphologic and climatic characteristics. It is recommended to separate basins with respect to their major factors into homogenous ...
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The hydrologic events and physical structure of a basin is related to governing climatic conditions. Basins have different hydrologic responses considering their various morphologic and climatic characteristics. It is recommended to separate basins with respect to their major factors into homogenous groups with the same hydrologic conditions. This grouping is effective so that models for estimating flood peak discharge in each homogenous group have higher performance than a single model for all basins. In this research, firstly different morphological characteristic of selected basins were derived using GIS. Based on factor analysis, major variables (factors) including; basin area, weighted-average slope, drainage density and annual mean precipitation were selected. Then, all basins were classified in homogenous groups with respect to major factors using cluster analysis and discriminate functions analysis, statistical methods, and Andrew’s curve as a graphical method. To investigate on the efficiency of grouping, two control basins were selected and their similarity to each homogenous group was carried out using above methods. By applying regression models developed for whole region and homogenous groups, flood peak discharges for two basins with different return periods were estimated. Simulated values compared with observed data and showed that models for homogenous groups have better performance than those for the whole region.
Mahmood Arabkhedri; Kolsoum Sedarati; Abazar Esmali
Abstract
Based on expert estimates, many Iranians believe that the amount of sediment yield is annually increasing. This study has attempted to assess the temporal trend in Suspended Sediment (SS) of Jajroud and Karaj rivers at Roudak and Sira stations. respectively with adequate data collected during four decades. ...
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Based on expert estimates, many Iranians believe that the amount of sediment yield is annually increasing. This study has attempted to assess the temporal trend in Suspended Sediment (SS) of Jajroud and Karaj rivers at Roudak and Sira stations. respectively with adequate data collected during four decades. The SS yield data and SS concentration as well as flow rate data were analyzed. Preliminary investigation showed that more than 92 percent of the SS at Roodak and Sira stations is transferred by top two and three flow deciles (equal to 20 and 30 percent) of the effective or flood discharges. Among these, the highest decile (10 percent) is responsible for carrying about 80 and 64 percent of SS accounted for the two study sites correspondingly. Therefore, mainly analyzing the highest decile flow data was considered. Four techniques were performed including: a) fitting regression lines to the measured SS concentrations and weights vs. time, and b) graphical comparisons of dependent variables (average discharge, average SS concentration and weight) during the four decades, c) using the Kruskal–Wallis test, and d) using Kendall rank correlation coefficient. All interpretation techniques showed decreasing trends vs. time which were significant based on the two nonparametric techniques. Since, the highest decile of daily flows of study sites have not shown any increasing trends during study period, it can be concluded that unlike the general publics’ believes the amount of SS has decreased. A possible explanation for this descending trend might be as a result of 43 and 25 conservation projects implemented during recent 30 years in the upstream basins of Amirkabir and Latian dams, respectively. The descending SS trend does not necessarily mean lower rates of erosion in these basins; but it rather means lesser sediment delivery ratios.
Morteza Miri; Mohammadreza Kousari; Mehran Zand
Abstract
One of the most common and effective problems in long-term climate studies is the presence of gaps in the time series of various climatic and hydrological data. Therefore, the present study evaluates the accuracy of methods for infilling missing data of daily, monthly and annual temperature time series ...
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One of the most common and effective problems in long-term climate studies is the presence of gaps in the time series of various climatic and hydrological data. Therefore, the present study evaluates the accuracy of methods for infilling missing data of daily, monthly and annual temperature time series in the arid regions of Iran. For this purpose, the observed daily minimum, average and maximum temperature data for the period 1987-2014 measured at 73 synoptic stations distributed all over arid regions of Iran were used. Methods of readjustment used include: Normal ratio method, linear regression, multivariate regression and Inverse Distance Weighting (IDW). In this study, the capability of each mentioned methods for infilling missing data of daily, monthly and annual precipitation time series in the arid regions of the Iran was investigated, while the proportion of missing data varies from 5 to 50% of total data. In order to compare and evaluate the accuracy of the four mentioned methods three statistical indicators, namely the correlation coefficient (R), the Root Mean Square Error (RMSE) and Nash coefficient were used. The results showed that in general, each of the methods mentioned had different functionalities at a special level of readjustment and time scale. On annual and monthly scales, linear regression and normal ratio methods are the most accurate method in readjustment temperature data in the arid region of Iran. The correlation value between the readjustment and observational data at different levels reaches more than 0.95 using these methods. On the daily scale, there is no significant difference between the accuracy of the methods used in the readjustment of temperature data, and almost all four of these methods have appropriate accuracy because in all methods the correlation between readjustment and observed data is more than 90%. However, multivariate regression methods with an average correlation of 0.99 showed the most accurate performance in readjustment daily data at different levels of readjustment. Generally, each method should be used in accordance with the conditions, and therefore it is recommended to develop a software package for infilling missing data.
Ali Ahani; Seyed Saeed Mousavi Nadoshani
Mehran Zand; Morteza Miri; Mohammadreza Kousari
Abstract
Climate change can lead to changes in the frequency, intensity, and duration of extreme climate events in different parts of the world. The purpose of this research is to investigate temperature and precipitation extremes in Lorestan Province. The data used in this study included precipitation and the ...
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Climate change can lead to changes in the frequency, intensity, and duration of extreme climate events in different parts of the world. The purpose of this research is to investigate temperature and precipitation extremes in Lorestan Province. The data used in this study included precipitation and the maximum and minimum daily temperature of nine synoptic stations in Lorestan Province during a 28-year (1990-2017) common period. The matrices of minimum and maximum temperatures and precipitation daily data for each station were prepared and used to compute the extreme climate indices (26 precipitation and temperature extreme indices based on the recommendation of CLIVAR \ CLL expert group) using the R programming software. The results of studying the trend of cold and hot extreme weather indicators during the period 1990-2017 in the province using the Mann-Kendall trend test showed that for all stations, the hot indices have increased and more cold indices have decreased. In different regions of the province, positive and negative trends of hot and cold indices with different intensities have occurred. The highest upward trend of the warm extreme indices has occurred for the hot night’s index. Among the cold indicators, the greatest decrease occurred for several frost days and cold days indices. The decreasing trend of ice days is significant for 45% of stations at 99% level and the decreasing trend of cold days for 77% of stations at different levels of 90, 95, and 99%. The results of the study of the frequency of occurrence and trend of precipitation extreme indicators in Lorestan province showed that the total rainfall of this province, like many regions of the country, has decreased. In contrast, the occurrence of maximum rainfall in addition to being significant in the province has an increasing trend during the period 2017-1990. These conditions can indicate an increase in the number of occurrences of heavy and short-term rainfall events and, shorten the period of the rainfall season in the region.
Pari Saeidi; Seyed Hamidreza Sadeghi; Abdulrasul Telvari
Abstract
Sediment graph is an important tool for soil and water resources management of watersheds. It is therefore important to find an appropriate procedure to simulate sediment graph data in different watersheds with inadequate and unreliable suspended sediment data. However, achieving simple procedures based ...
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Sediment graph is an important tool for soil and water resources management of watersheds. It is therefore important to find an appropriate procedure to simulate sediment graph data in different watersheds with inadequate and unreliable suspended sediment data. However, achieving simple procedures based on easily accessible data has been less considered. Hence, the present study was conducted in Galazchai Watershed in West-Azerbaijan Province, Iran, with an area of some 103 km2 to investigate the ability of synthetic sediment graph development by using hydrograph. Towards this attempt, a databank of 18 storm events occurred during autumn 2011 and spring 2014 was developed and corresponding total and direct hydrographs and sediment graphs were prepared. All total and direct sediment graph components were simulated using corresponding hydrograph components with the help of different bivariate regression models and the best performed model was ultimately determined by applying different criteria. The results showed that the simulation of different total sediment graph components was possible using hydrograph components except for base time and ordinates of 50 and 75 percent of peak. Direct sediment graph simulation results also verified the simulation ability of all components except for ordinates of 75 percent of peak. According to the results, simulation of temporal components with the lower relative errors had better performance than the other components. So that, for total sediment graph, the lowest relative estimation and validation errors for time to peak were 48.86% and 45.65%, respectively. Also, the best performed model developed for the direct sediment graph base time had the lowest relative estimation and validation errors of 23.03% and 21.75% and the highest coefficient of efficiency of 0.93.
Aiding Kornejady; Hamid Reza Pourghasemi
Abstract
The current study is aimed to map landslide susceptibility in the Chehel-Chai Basin is located in the Golestan Province. To this end, two data mining models namely support vector machine and boosted regression tree were employed due to their robust computational algorithm. Landslide inventories were ...
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The current study is aimed to map landslide susceptibility in the Chehel-Chai Basin is located in the Golestan Province. To this end, two data mining models namely support vector machine and boosted regression tree were employed due to their robust computational algorithm. Landslide inventories were recorded through several field surveys using global positioning system (GPS), local information and available organizational resources and corresponding map was created in the geographic information system (GIS). Reviewing several worldwide studies, 12 predisposing factors including proximity to fault, proximity to stream, proximity to road, lithological units, soil texture, land use/ cover, slope degree, slope aspect, altitude, plan curvature, profile curvature and topographic wetness index (TWI) were chosen and the corresponding maps were produced in the geographic information system. In order to evaluate models’ results the receiver characteristic curve (ROC) and 30% of landslide inventories were used. Results showed that the SVM model with the AUC value of 0.82 had better performance on landslide susceptibility zonation over the study area and followed by the BRT model with the value of 0.77. Based on the SVM model results, about 45% of the Chehel-Chai Basin has high and very high landslide prone areas.
Shahriar Sobh Zahedi; Ramin Naghdi; Mohammad Reza Gharibreza; Ali Salehi; Ghavamoddin Zahedi Amiri
Abstract
The method employed in this study was based on experimental research and field study. In this method, the stored radiocesium of the forest region which was supposed to be converted into Poplar plantation has been compared with the stored radiocesium of the reference region. 11 core samples were taken ...
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The method employed in this study was based on experimental research and field study. In this method, the stored radiocesium of the forest region which was supposed to be converted into Poplar plantation has been compared with the stored radiocesium of the reference region. 11 core samples were taken from reference region and then 7 core samples were selected from the transect which was a part of Poplar plantation that were taken by topographic characteristics in a depth of 25 centimeters, Having prepared the core samples according to the IAEA, they were packaged into the special Gama spectrometer containers. After that the amount of radiocesium of all samples has been measured by Bq kg-1 scale. The findings revealed that the amount of radiocesium in reference region was computed as 5894.1. Bq m-2 y-1. In the present study, soil loss rate during transect was estimated using proportional conversion models and mass balance I and II of 18.70, 22.72 and 18.64 ton / ha, respectively. These values were obtained for slope of 10-20%, canopy cover of 25% and clay loam soil under 1000 mm precipitation. This study recommended mass balance model II for estimation of erosion in changed land use areas and concluded that forest land use change to plantation due to reduction of long soil cover and plantation management by removing other seedlings and herbaceous cover increased the rate of soil erosion occurs. This process for many years has caused the erosion rate to exceed and has caused the loss of 0.1 cm of soil per year.
Hasan Nikkhou; Amin Salehpour Jam; Zahra Gerami
Abstract
Introduction
Today, the natural resources of the country face serious problems and threats such as water scarcity, drought, climate change, water pollution, soil and air pollution, desertification, soil erosion, and issues arising from unsustainable and inappropriate land use practices such as deforestation, ...
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Introduction
Today, the natural resources of the country face serious problems and threats such as water scarcity, drought, climate change, water pollution, soil and air pollution, desertification, soil erosion, and issues arising from unsustainable and inappropriate land use practices such as deforestation, destruction of rangelands, overgrazing, and unsustainable agriculture. This underscores the urgent need for a more serious focus on the issue of research and sustainable development in the management of the country's natural resources and environment to provide solutions to problems and improve the health and sustainability of the country's ecosystems. Despite the abundance of research articles in the field of watershed management with an emphasis on its technical and managerial aspects published in domestic and international journals, the categorization and thematic analysis of scientific research articles published in domestic journals have received less attention. In this regard, this study aims to investigate the thematic analysis and classification of various types of articles published in the Watershed Engineering and Management Journal, as well as to examine the thematic trends of each category over three five-year periods.
Materials and methods
This study was conducted with the aim of examining and evaluating the articles published in the "Watershed Engineering and Management" journal during the period from 1388 to the end of 1402 (Volume 15, Issue 4). In this regard, the first step was to classify the types of published articles thematically. Additionally, to examine the frequency of various types of articles published in the relevant specialized categories, as well as the frequency of keywords presented in these articles, three time periods were considered, including the periods from 2009 to 2013 (Volumes 1 to 5), 2014 to 2018 (Volumes 6 to 10), and 2019 to 2023 (Volumes 11 to 15). Furthermore, in this study, an investigation was conducted into the perspectives of faculty members and research experts of the five research groups of the Soil and Watershed Conservation Research Institute regarding the submission of articles to the "Watershed Engineering and Management" journal, as well as the quality, characteristics, challenges, and functions of articles published in this journal during the period from 2009 to the end of 2023 (Volume 15, Issue 4). In this regard, after categorizing the types of published articles thematically by the five research groups and designing relevant questionnaires, a survey was conducted regarding the role of selected factors in submitting articles, as well as the types of published articles categorized by each group, based on a questionnaire consisting of 11 qualitative ordinal variables and scoring according to the Likert pentagon spectrum. After examining the validity and reliability of the measurement tool and determining the sample size using the Cochran formula, descriptive statistical analysis was employed in this study to analyze the results.
Results and discussion
In this study, articles were categorized into 12 thematic classes based on their titles. The results indicate that the thematic categories of "Hydrology" and "Horticulture" have the maximum and minimum frequencies, respectively. The findings reveal that the number of articles presented in the categories of "Climate", "Geomorphology", "Management", "Hydrology", and "Hydrogeology" shows an ascending trend over the triennial periods of 2009 to 2013 (Volumes 1 to 5), 2014 to 2018 (Volumes 6 to 10), and 2019 to 2023 (Volumes 11 to 15). The results also show that the five keywords "Geographic Information System", "Runoff", "Soil Erosion", "Sediment", and "Remote Sensing" have the highest frequency in the articles published during the period from 2009 to the end of 2023 (Volume 15, Issue 4). Furthermore, the results indicate that all research groups have given higher than average scores for selecting this journal as the first choice for publishing their articles. Additionally, factors such as "Review and Publication Time", "Review and Publication Costs", and "Ease of Working with the Journal System (Sina Web)" play an important role in encouraging researchers to submit articles to this journal, with average scores above average and more than average. This is while the roles of editorial board members, chief editors, editors-in-chief, internal, and executive managers in submitting articles to this journal have varying degrees of importance, ranging from low to less than high. Moreover, the survey results show that the five research groups have given scores higher than average to less than very high to the alignment of article topics with the journal's focuses.. In this regard, articles related to the expertise of the Watershed Management research group have the highest alignment (from high to very high) with the journal's focuses. This is while the innovation of articles is mostly average, which is evaluated as less than average to average for articles related to the expertise of the Drought and Climate Change research group. Furthermore, the results indicate that the level of application of innovative research tools and methods in the articles of this journal is mostly average to less than high. Additionally, the subject matter of the articles published in this journal is mostly scored higher than less than average to less than high for addressing the country's needs and challenges. This is less than average for articles related to the River Engineering and Coastal Protection group and between average to less than high for other groups. Except for the Drought and Climate Change group, the application of the results and achievements of these articles in the description of detailed-executive watershed studies is less than average. This highlights the urgent need for a review of the description of detailed-executive watershed studies by the Natural Resources and Watershed Management Organization.
Conclusions
The results indicate that the thematic categories of "Hydrology" and "Horticulture" have the maximum and minimum frequencies, respectively. Furthermore, the number of articles presented in the categories of "Climate", "Geomorphology", "Management", "Hydrogeology", and "Hydrology" shows an ascending trend over the three five-year periods. Additionally, the keywords "Geographic Information System", "Runoff", "Soil Erosion", "Sediment", and "Remote Sensing" have the highest frequency in the articles published in this journal during the period from 2009 to 2023. Regarding the inclination and influential factors in submitting articles by the faculty members of the Soil and Watershed Conservation Research Institute to this journal, the results indicate that all research groups have given scores higher than average for selecting this journal as their first choice for publishing their articles. Additionally, factors such as "Review and Publication Time", "Review and Publication Costs", and "Ease of Working with the Journal System (Sina Web)" play an important role in encouraging researchers to submit articles to this journal, with average scores above average and more than average. The results indicate that the five research groups have given scores ranging from above average to less than very high for the alignment of article topics with the journal's focuses. This is while the innovation of articles and the level of application of innovative research tools and methods in the articles of this journal are respectively at an average and less than high level. Additionally, the results of evaluating the quality of article publication in this journal, in terms of aspects such as editing, formatting, and illustration clarity, suggest a relatively good status (above average to less than very high) for the journal. Furthermore, the subject matter of the articles published in this journal is mostly scored higher than less to less than high for addressing the country's needs and challenges. Also, except for the Drought and Climate Change group, the application of the results and achievements of these articles in the description of detailed-executive watershed studies is less than average. The current evaluation can serve as a model for examining and analyzing other journals and improving the quality of various scientific content published in them.
Rahim Kazemi; Jahangir Porhemmat
Abstract
Understanding the base flow can be useful in river flow analysis, rainfall-runoff modeling, calibration of models, water resource management in low flow conditions and determination of the amount of water storage in watershed. In this research, 22 stations were selected with the appropriate data and ...
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Understanding the base flow can be useful in river flow analysis, rainfall-runoff modeling, calibration of models, water resource management in low flow conditions and determination of the amount of water storage in watershed. In this research, 22 stations were selected with the appropriate data and common period of the years of 1982-2012. The trend of flow changes during the months of the year was determined for all hydrometric stations in the study area and the driest month was determined. Then, the calibration of six recursive digital algorithms was performed using the long-term data of the driest month of the year and after obtaining optimal parameters of the models, the base flow separation for the whole period was performed. The performance evaluation of the models was done using root mean square error. The results showed that the major part of the river flow in the study area was related to the base flow and the minimum, maximum and average annual base flow index for the whole period was equal to 0.48, 0.62 and 0.56, respectively, representing more than 50% of ground water contribution to stream flow of the studied watersheds. Results of the evaluation of the models using the root mean square error showed that the mean error in the research area for all the methods ranged from 0.025 to 0.044. The minimum was related to Lynie and Holick, and the maximum related to the One-parameter digital filter. Over all, conclusion of the results of the calibration process and investing the correlation between calculated and measured data showed that there was a correlation with a coefficient of explanation of more than 80%. Calibration method with dry season data in the absence of tracer-based methods is suggested as the most suitable method for calibrating digital separation filters in the study area.
Jamshid Yarahmadi; Davood Nikkami; Ali Shahnavazi; Mohammad Ebrahim Sadeghzadeh
Abstract
Watershed residents' benefit increasing and soil erosion controlling are the main goals of agricultural sustainable development. Landuse optimization operation is an effective solution in order to maximizing the benefits, as well as minimizing soil erosion damages. Current research was executed in southern ...
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Watershed residents' benefit increasing and soil erosion controlling are the main goals of agricultural sustainable development. Landuse optimization operation is an effective solution in order to maximizing the benefits, as well as minimizing soil erosion damages. Current research was executed in southern parts of Ahar Chaey Watershed in East Azerbijan Province. In this research, Multi-Objective linear programing based on Simplex method applied for optimizing landuse in form of three different scenarios: current landuses, implementation of management into current landuses and performance of the standard landuses by WinQSB software. Results showed that due to landuse optimization, irrigated orchards could be increased from 1.736 to 6.629 km2. In addition, based on suitable soils and adequate rainfalls, it is expected to expand the rainfed orchards up to 9.72 km2. Also, the weighted average of soil erosion reduces from 16.3 to 14.8 and from 10.11 to 9.5 tha-1year-1 within the first and second scenarios, respectively. This rate will reduce up to 6.8 tha-1year-1 in the standard landuse situation. On the other hand, maximizing results showed that the annual net benefits increases from 6.6 to 12.9 and 8.46 to 14 million Rails per unit area in the first and second scenarios, respectively. This rate increases up to 15.67 million Rails per unit area for standard landuse situation. Sensitivity analysis results showed that irrigated and rainfed orchards are of high sensitivity in maximizing profit functions due to high profitability of these landuse in unit area. In contrast, the rangelands, forests and drylands are of high sensitivity in soil erosion minimization, so that with increasing their area, soil erosion will increase significantly in the region.
Raouf Mostafazadeh; Amir Sadoddin; Abdolreza Bahremand; Vahedbordi Sheikh; Habib Nazarnejad
Volume 2, Issue 2 , July 2010, , Pages 83-93
Abstract
Assessment of flood control projects in the same conditions is essential in order to improve decision making that assist us in watershed management purposes. Focus of this study is on assessing hydrological effects of the Jafar-Abad watershed management project. The study area (109 km2) located in north ...
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Assessment of flood control projects in the same conditions is essential in order to improve decision making that assist us in watershed management purposes. Focus of this study is on assessing hydrological effects of the Jafar-Abad watershed management project. The study area (109 km2) located in north of Iran in the Golestan province. Paired t-tests were performed for Indicators of Hydrologic Alteration (IHA) in Taghi-Abad gauging station, located in the outlet of the catchment, before and after construction of 58 check dams. HEC-HMS model was calibrated using 12 storm events and validated for study area. Calibrated HEC-HMS model was applied to rainfall-runoff modeling in sub-catchments and Level-pool method used for reservoir elements. Design flood hydrographs for 2-100 year return periods were simulated for both before and after check dams construction periods. The results of statistical analysis indicate that existing flood control measures had no significant impact on the hydrologic characteristics measured by IHA in 95% confidence level. The results indicated that constructed structures do not have important effect on IHAs and the amount of these effects was less than 1.5 percent in all cases. Also, by increasing in return period, the effects of structures on peak discharge and flood volume were reduced.
Seyed Ahmad Hosseini; Nasrolah Javaheri; Mehdi Habibi
Abstract
This study investigated the status of sediment transport and deposition in Khar-rud River, Qazvin province, Iran. The aim was to determine the possibility of construction of sand and gravel mining workshops in the margin of Khar-rud Flood-plain. Here with calculating sediment transport rate and specifying ...
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This study investigated the status of sediment transport and deposition in Khar-rud River, Qazvin province, Iran. The aim was to determine the possibility of construction of sand and gravel mining workshops in the margin of Khar-rud Flood-plain. Here with calculating sediment transport rate and specifying the distribution of sediment deposits in various parts of the river, an applied program for sand harvesting from the river bed, is developed. In this project, after preparing the basic information, such as information about river geometrical shape, roughness coefficients of different sections, information related to size gradation of suspended sediments and bed material, river hydrology data and boundary conditions of downstream hydraulic system, using HEC-RAS model, sediment loads and its distribution along the river was simulated. Simulation was done based on classified data from daily flow discharges during a 37-year period. After calibrating the HEC-RAS model and selecting Yang sediment transport equation as the closest relationship to the sedimentary data measured by regional Hydrometric stations, the average volume of sediment yield from the river was estimated 1.75 million tons per year. Finally, considering the changes in the river bed elevation for each cross-section, the amount of sediment passing during simulated 37-year was calculated. Using the results of the model and sedimentation changes along the study reaches, the volume of sediment transport in each river cross section, the river width and its private region and considering the maximum permissible depth of bed-material removal equal to 1 m, the most suitable mining length and period in the different reaches of river was determined, discussed and showed in ARC-GIS environment. Based on simulation results, the average depth of sand which can be taken safely from the river-bed was estimated to be 40cm and the most suitable period of time for sand mining along the river was recommended from January to May. It was determined that HEC_RAS hydraulic model, covers about %63 of initial engineering judgments for the amount and location of sand mining.
Rahim Kazemi; Ali Reza Eslami
Abstract
Base flow and related index is influenced by morphometric, geologic and hydroclimatological factors. As a result, it is precondition data for planning and water resources management. In this research, base flow and related index were extracted from daily stream flow data using one parameter recursive ...
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Base flow and related index is influenced by morphometric, geologic and hydroclimatological factors. As a result, it is precondition data for planning and water resources management. In this research, base flow and related index were extracted from daily stream flow data using one parameter recursive digital filter in eighteen hydrometric stations of the Caspian Basin. Physiographic, climatic, hydrological, and geological factors were calculated in GIS environment. Using factor analysis of the eighteen parameters, five factors were selected as independent factors. Statistical models were formulated to calculate several regressions between hydroclimatological and physiographic parameters. Further, residual analysis method was used to compare and evaluate the accuracy and efficiency of the models. Results showed that Hard Formations, the average height of basin, drainage density, and coverage of forest were the best predictors of the base flow index. Statistical models highlights importance of Q90/Q50 ratio as the suitable hydrologic index to estimate the base flow index. Besides, this model confirmed controlling role of Hard formations and the forest coverage on the base flow index.
